Gel:(pronounced "jel") Semi-transparent heat-resistant material which is placed in front of a light source in
order to modify it's colour temperature or other characteristics.Related info: Color Temperature

Geosynchronous:A satellite orbit in which the satellite remains in a fixed position above the Earth.

Gray Card:A gray-coloured card which reflects a known, uniform amount of the light which falls upon it. Used as a reference to calibrate light meters and set exposure.More Info: Grayscale Chart, 18% Gray Card

Gray Noise:Random noise, similar to white noise, which has been filtered to make all frequencies appear equally loud to the human ear.
More info: Gray noise, Noise colors

Green Noise:An unofficial term referring to the background ambient noise of the world. Can also mean the mid-frequencies of white noise.More info: Green noise, Noise colors

Green Room:A room located near the main stage in a studio or concert venue, where artists and guests wait before their appearance.More info: Green room

Green Screen:A film and video technique in which action is shot against a green screen, which is subsequently removed from the image and replaced with a different background. More info: Green Screen , Chroma Key

Grip:Person who is responsible for constructing and dismantling film sets, as well as laying down dolly tracks.